Mitosis
A student observes a cell with chromosomes that are duplicated but not yet aligned at the cell’s equator. The nuclear membrane is breaking down. This observation best supports that the cell is in this phase.
What is Prophase?
Meiosis produces gametes which are _____loid.
What is haploid or monoploid?
This law states that allele pairs separate during gamete formation so each gamete carries only one allele for each trait.
What is the Law of Segregation?
This pattern of evolution occurs when unrelated species develop similar traits due to living in similar environments.
What is Convergent Evolution?
This evolutionary mechanism involves the random change in allele frequencies in a population, especially in small populations.
What is Genetic Drift?
A researcher applies a drug that prevents spindle fibers from forming. Cells exposed to this drug would most likely fail to complete this process.
What is chromosome separation during Anaphase?
This process during meiosis increases genetic variation by exchanging segments between homologous chromosomes during what phase?
What are a) crossing over during b) Prophase 1?
This law explains why traits controlled by different genes are inherited independently of one another when the genes are on different chromosomes.
What is the Law of Independent Assortment?
This pattern of evolution explains how one ancestral species can give rise to many different species with diverse adaptations.
What is Divergent Evoution?
This process occurs when individuals move between populations, introducing new alleles and increasing genetic diversity.
What is Gene Flow?
A mutation causes sister chromatids to remain attached during mitosis. What is the most likely result in the daughter cells?
What is unequal distribution of chromosomes in the daughter cells
A cell begins meiosis with 46 chromosomes. After meiosis II, each resulting cell will have this number of chromosomes.
What is 23 chromosomes?
A heterozygous tall plant (Tt) is crossed with a short plant (tt). According to Mendel’s laws, this is the expected phenotypic ratio of the offspring.
What is a 1:1 ratio of tall to short plants?
Sharks and dolphins both have streamlined bodies for swimming, even though they are not closely related. This is an example of this evolutionary pattern.
What is Convergent Evolution?
A hurricane randomly wipes out a large portion of a small island population, leaving only a few survivors whose alleles shape the future population. This is an example of this type of genetic drift.
Waht is the Bottlelneck Effect?
Two cells undergo division. Cell A completes mitosis; Cell B undergoes a process that results in genetically different cells. Based on this observation, Cell B most likely underwent this process instead of mitosis.
What is Meiosis?
A cell in meiosis I fails to separate homologous chromosomes. This error would most likely result in gametes with this condition.
What is abnormal chromosome number due to Nondisjunction?
A dihybrid cross does not produce the expected 9:3:3:1 ratio. This suggests that the genes involved are most likely exhibiting this condition.
What is genetic linkage (genes located close together on the same chromosome)?
Two species share a common ancestor, but over time they develop different traits due to different environmental pressures. This pattern of evolution is best described as this.
What is Divergent Evolution?
Two populations of the same species begin to show less genetic difference over time because individuals frequently migrate between them. This pattern indicates the action of this evolutionary mechanism.
What is Gene Flow?
A scientist compares normal cells to cancer cells and finds that cancer cells bypass cell cycle checkpoints before mitosis. This allows cancer cells to do this.
What is divide uncontrollably?
A scientist claims that meiosis produces genetically identical cells, just like mitosis. Based on evidence from meiosis, this claim is best evaluated as this.
What is incorrect, because meiosis produces genetically diverse cells due to crossing over and independent assortment?
A scientist argues that Mendel’s laws apply universally to all traits. Evidence from traits like incomplete dominance or gene linkage leads to this evaluation of that claim.
What is that the claim is too simplistic or not fully accurate because Mendel’s laws have exceptions?
A scientist claims that species with similar physical traits must be closely related. Evidence from analogous structures leads to this evaluation of the claim.
What is that the claim is not always correct because similar traits can evolve independently (convergent evolution)?
A scientist claims that genetic drift always increases genetic diversity in populations. Based on evidence, this claim is best evaluated as incorrect because genetic drift can occur in small populations. Give an example of this.
A classic example of genetic drift in a small population is the founder effect.
For example:
A small group of birds gets blown to an island during a storm. In the original population, feather color alleles were evenly mixed. But the few birds that arrived mostly carried the allele for dark feathers.
Over generations, the island population ends up with mostly dark-feathered birds, not because it’s advantageous, but simply due to chance.